Little is known about the pathogenesis of cerebral atrophy or its association with intellectual functioning in normal and pathological aging. This investigation will study the association between cerebral atrophy, as measured by computerized transverse axial tomography (CT scan), aging, and intellectual functioning in two related studies. First, it will study the association of cerebral atrophy and current intellectual functioning with prior assessment of risk for coronary heart disease (CHD) in an otherwise healthy group of males, aged 65-79. Secondly, it will examine the relationship between cerebral atrophy and measures of intellectual functioning in the above group and in elderly persons suspected of dementia. In addition, the design of the study will permit an analysis of the differential effect of aging on cerebral atrophy, and on intellectual functioning. Subjects with known prior cardiovascular risk status will be selected by stratified sampling from among the surviving annuitants of a long-term epidemiological study. Persons referred for evaluation of suspected dementia will be sequentially selected according to the degree of cerebral atrophy on CT scan. A CT scan, routine laboratory and diagnostic tests, and psychological test data will be obtained from all subjects. Statistical analyses will determine the interrelationships among age, intellectual functioning, cerebral atrophy and CHD risk. The study will clarify the relationship of diffuse cortical degenerative changes to duration and severity of risk status for coronary heart disease on the one hand, and to intellectual functioning on the other.